Renal system Flashcards
what hormone controls Na+?
aldosterone
what hormone controls amount of water?
ADH
the kidneys have a major influence on what hemodynamic
blood pressure
what is the functional unit if the kidney
Nephron
metabolic end-prodeucts are excreted how?
filtration
(they are filtered into, and then trapped within, the renal tubule)
Renal Functions:
what are the main electrolytes the kidney balances?(5)
Na+
K+
Ca++
Mg++
Cl-
Renal Functions:
what 2 things does it control for acid base balance?
H+
HCO3-
Renal Functions: regulation of osmolality
________ are 90% of total osmolality of the ECF
sodium salts
Renal Functions: regulation of osmolality
when we talk about regulating osmolality, we are talking about regulating what?
Sodium concentration
(b/c sodium salts represent 90% of total osmolality)
Renal Functions: regulation of osmolality
what is normal osmolality? give normal and range!
normal 300 mOsm/kg
range 270-310 mOsm/kg
Renal Functions:
what are 6 non-volatile end products of metobolism excreted
HP04 –
SO4 –
urea
Creatinine
uric acid
lactic acid
Maintenance of ECF volume is acheived by controlling what 2 things
salt NaCl
and
water excretion
the kidneys are considered endocrine why?
they produce hormones
What 3 hormones to the kidneys produces
Erythropoietin
Renin
Vitamin D
Endorince functions:
what does erythropoietin do?
acts on bone marrow and stimulates RBC production
Endorince functions:
whay is a pt with chronic renal failue anemic
decreased production of erythropoietin
Endorince functions:
what is the purpose of renin
enzyme that participates in blood pressure regulation, potassium ecretion, and sodium reabsorption
Endorince functions:
function of vitamin D
the kidney w/ help of the liver convert Vit D into its active form Vit D3
Endorince functions:
why does a chronic renal pt become hypocalcemic
b/c absorption from the intestine is impaired when there is a vit d if difficient
Renal Blood flow:
the kidney receives what % of CO
25%
1.25 L/min
how do the kidneys autoregulate
they have 2 sets of capillaries, the dual function allows for control of flow and pressure
Label
- Efferent Arteriole
- proximal convoluted tubule
- Loop of henle
- Afferent Arteriole
- Distsal convoluted tubule
- Collecting duct
Point or explain where each diuretic works
CAI
Loop
Thiazides
K+ sparing
CAI- proximal tubule
Loop- thick Ascending loop oh henle
Thiazide- distal tubule
K-sparing- collecting duct
point to the bowmen’s capsul
point to the glomerulus
three functions of the kidney
filtration
reabsorption
secretion
what is the function of the proximal tubule
reabsorbs the bulk of the filtered fluid and it’s dissovled contents
what is the function of the Loop of Henle
establishes and maintains an osmotic gradient in the medulla.
what is the function of the distal tubule and collecting ducts?
make final adjustments on urine pH, osmolality, and ionic composition
the LOH is a COUNTERCURRENT MULTIPLIER which does what
creats the osmotic gradient
the vasa recta is a COUNTERCURRENT EXCHANGER whch does what?
Maintains the osmotic gradient of the LOH
the Thick acending LOH is impearmeable to what?
water
explain the osmolality of the cortical and medullary tissue from cortex to inner medulla
in the cortex osmolality 300
in the outer medulla increases from 400 - 600
in the inner medulla increass from 800 to 1200
The osmolality increases as it travels throught the nephron
picture to expain osmolality of cortical and medullary tissue
deposition of Na+ into the medullary interstitium by the TAL of henle can increase the interstitial osmolality to 600 mOsm/kg. where does the additional 600 come from- for a total of 1200 at the tip of the medullary pyramid?
urea
the bullk of the glomerular filtrate (67%) is reabsorbed by what?
proximal tubule
Renal control of glucose:
what part of the nephron has the maximum capacity for reabsorbing glucose
proximal tubule
Renal control of glucose:
just to read and understand
the proximal tubule has the maximum capacity for reabsorbing glucose; this maximum reabsorption capacity is referred to as the transport maximum (Tm). all of the filtered glucose is normally completly reabsorbed from the the proximal tubule y active transport mechanisms. the amount of filterd glucose normally does not exceed the transfer (transport) maximum. in untreated DM, the amount of glucose filtered exceeds the transfer (transport) maximum of the proximal tubule. glucose that escapes reabsorption from the proximal tubule is excreted. all segments of the renal tubule beyond the proximal tubule are impermeable to glucose.
picture to explaint the renal control of glucose
what happens to urine output in the untreated pt w/ DM? why?
UOP increases, bc unfiltered glucose load exceeds the transport maximum; glucose the remains in the tubular fluid after PCT causes osmotic diuresis
renal control of water excretion:
the rate of ADH released into the bloodstream is directly related to the what of the ECF?
osmolality
renal control of water excretion:
besides osmolality, what other 2 things can trigger release of ADH
decreases in ECF volume
stressors (pain)
renal control of water excretion:
an INCREASE in ECF osmolality is corrected how
ingesting water and adding to the ECF
renal control of water excretion:
a decrease in ECF osmolality is corrected how
by excreting water and removing it from ECF
renal control of water excretion:
ECF osmolality (hence sodium concentration) is regulated by what?
ADH
also called AVP (arginine vasopressin)
AVP/ADH:
synthesized where?
hypothalamus (paravetricular and Supraoptic nucleus)
AVP/ADH:
stored where
post pituitary
neurohypophysis
AVP/ADH:
secreted into what
blood
AVP/ADH:
stimulus for release
increased Na+
Increased osmolality
AVP/ADH:
site of action
collecting ducts
2 hormones the neurohypophysis releases
ADH
Oxytocin
6 hormones the andenohypophysis releass
GH
ACTH
FSH
Prolactin
LH
TSH
how do you tell the orientation of the pituitary gland in a picture
CN II the optic chiasm (anterior)
in response to an increase in ECF osmolality what occurs
paraventricular and supraoptic nuclei shrink and nerve axons fire action potential, which cause AVP/ADH release from the neurohypophysis
what is the most powerful stimulus for triggering the release of AVP/ADH
increase in ECF osmolality
when AVP/ADH reaches the collecting duct what occurs
reabsorption of water increases
in response to a decreas in ECF osmolality what occurs in the hypothalamus
cells of the paraventricular and supraoptic nucli swell and nerve action potentials are inhibited so AVP/ADH release is depressed.
in the absence of AVP/ADH what happens in the collecting ducts
they are impeameable to water and a large volume of dilute urine if formed
any stress (hypovolemia, hypotension, pain, emotional) will cause what regarding the release of AVP/ADH
lead to an increase in the release
extracellular fluid volume:
what is the major determinant of ECF volume
amount of Na+ in the body
extracellular fluid volume:
what is the most important hormone in regulating ECF volume
aldosterone
aldosterone is produced where?
zona glomerulosa of the adrenal cortex
where does aldosterone work
distal convoluted tubule
what does aldosterone do?
increases the rate of Na+ REABSORPTION, therby decreases the rate of Na+ elimination
what does aldosterone do to K+
increases the rate of K+ secretion into the late DCT and collecting duct therby increasing the rate of K+ excretion
when sodium intake is high, the body Na+ content increases, and the body fluids become concentrated. ADH/AVP output increases to conserve water, and thirst causes water ingestion, which stores osmolality but expands fluid volume
what is the majar consequence of sodium retention
ECF volume expansion (hypervolemia)
and arterial bp to increase
a picture of body’s response to increased sodium
when the bodies sodium intake is low, the body sodium content decreases, and the body fluids become dilute. AVP/ADH output decreases, and a dilute high volume urine is formed. osmolality is restored, but fluid volume is contracted
what is the major consequence of Na+ loss?
fluid volume contraction (hypovolemia)
decreased arterial bp
picture showing body’s response to low Na+
Diuretics:
name some loop diuretics
Furosemide (lasix)
Bumetanide (Bumex)
Torsemide (demadex)
Diuretics: Loop
where do they work
Acending LOH
Diuretics: Loop
how do they work?
- the LOH simultaneously transports Na+, K+, and 2Cl- in the same direction (termed Na+, K+, 2Cl- symporter)
- Loop diuretics bind to the Na+, K+, 2Cl- symported and inhibit the reabsorption of these ions from the ascending LOH
- the amount of H20 reabsobed is reduced and watyer excretion increases
Diuretics: Loop
Side effects of Loop diuretics
- Hypokalemia
- Fluid volume deficit
- Orthostatic hypotension
- reversibel deafness
Diuretics: Loop
why can bp fall even before UOP increases
bc they trigger the release of prostaglandins that cause venodilation, the decreased prelad causes a decrease in bp
picture of Loop diuretics
diuretics that work on the DCT an dColecting duct work to inhibit what
Na+ reabsorption
thiazides inhibit Na+ reabsorption where
early DCT
where does spiralactone work
late DCT, early collecting duct (go with collecting duct)
spironolactone competively inhibits what?
aldosterone
give an ex on a Carbonic Anhydrase Inhibitor
Acetazolamide (diamox)
Carbonic Anhydrase Inhibitor inhibits what
the enzyme Carbonic Anhydrase
Carbonic Anhydrase Inhibitor works where
PCT
Carbonic Anhydrase Inhibitor does what to Intraoccular pressure and how
decreases the formation of aques humor, this decreaseing intraocular pressure.
Acute Kidney Injury:
formally called what
acute renal failure
Acute Kidney Injury:
periop renal failure accounts for ____ of all pts requiring acute dialysis
half
Acute Kidney Injury:
3 types
prerenal
intrarenal
postrenal
Acute Kidney Injury:
3 causes of prerenal
decreased renal blood flow
Hypovolemia
Decreased CO
(anything that occurs befor blood gets to kidney)
Acute Kidney Injury:
4 causes of Intrarenal failure
- renal tubular damage (tubular necrosis)
- Renal ischemia d/t prerenal causes
- Nephrotoxic drugs
- release of hemoglobin or myoglobin
(anything that occurs inside the kidney)
Acute Kidney Injury:
3 causes of postrenal failure
- Obstruction of urine flow
- Bilat ureteral obstrution
- extravasation d/t bladder rupture
(anything that occurs after the kidney)
Acute Kidney Injury:
what is a syndrome triggered by hypoperfusion of the kidneys resulting in te rapid deterioration of renal function and accumulation of nitrogenous wastes (azotemia)
ischemic Acute renal failure
Chronic Kidney disease:
normal GFR
125 ml/min
Chronic Kidney disease:
GFR for decreased renal reserve
50-80 mL/min
Chronic Kidney disease:
GFR for renal insufficiency
12-50 mL/min
Chronic Kidney disease:
GFR for uremia
Chronic Kidney disease:
what is the best test to show renal reserve
creatinine clearance (measures GFR)
Chronic Kidney disease:
3 main complications
Anemia
Pruitus
Coagulopathies
Chronic Kidney disease:
common electrolyte disturbances?
Hyperkalemia
Hypocalcemia
Hypermagnesemia
Hyperphosphatemia
Chronic Kidney disease:
what is the most serious electrolyte disturbance
Hyperkalemia
Chronic Kidney disease:
what fluid would u wanna avoid and why
LR
contains 4 mEq of k+
Chronic Kidney disease:
avoid elective sx unless K+ is less than what?
5.5
Chronic Kidney disease:
ways to treat hyperkalemia
Iv calcium
Hyperventilation
IV Insulin and glucose
IV Beta 2 agonist
IV loop diuretics
kayexalate
Dialysis
